Aerosol antimicrobial compositions

ABSTRACT

An aerosol antimicrobial composition is provided with the following ingredients: a) an anionic polymer or prepolymer; (b) a quaternary ammonium compound, the components (a) and (b) combining to form an antimicrobially effective complex; (c) at least one water-soluble or dispersible organic solvent having a vapor pressure of at least 0.001 mm Hg at 25° C., said at least one organic solvent present in a solubilizing--or dispersion--effective amount; (d) an effective amount of a propellant; and (e) the remainder, water. Further is provided a novel method of decontaminating a surface fouled with microorganisms and a dispenser for said aerosol composition. The novel composition advantageously has both disinfectancy (contact efficacy) and residual antimicrobial efficacy.

FIELD OF THE INVENTION

The present invention relates generally to dispensable antimicrobialcompositions, and more particularly to an aerosol composition which hasboth disinfectancy (contact efficacy) and residual antimicrobialefficacy.

BACKGROUND OF THE INVENTION

In the seemingly perpetual battle against infection by pathogenicmicroorganisms, a recent, alarming trend has been observed. Antibioticmedications and treatments long thought to have conquered, if notarrested, the invasive infection of humans by such pathogens (generally,prokaryotic organisms, such as bacteria), have recently begun to fail orlose effectiveness at stopping such infections. Terrifying, andseemingly increasingly frequent, news stories of either fatal or seriousinfection by such bacteria as the common intestinal inhabitantEscherichia coli 0.157 (especially affecting small children and thosewith a lesser, or challenged immune system), and by certain species ofStaphylococcus sp. (colorfully, but somewhat inaccurately dubbed in newsaccounts as "flesh eating bacteria") have led to the conclusion thatprevention, by decontamination of surfaces touched by humans, may indeedbe a wiser remedy than cure by antibiotics. So, the search forappropriate antimicrobial treatments of surfaces is spurred by this newchallenge by these old enemies of the human population.

The use of quaternary ammonium compounds as antimicrobial agents is wellknown in the art. See U.S. Pat. Nos. 2,746,928, 3,344,018, 3,719,711,and JP 01/046081. For instance, quaternary ammonium compounds have beenincorporated into polymer and liquid compositions to protect thecompositions themselves from microbial attack (i.e., used aspreservatives). See U.S. Pat. Nos. 3,471,423, 5,028,619 and 5,399,343.Furthermore, quaternary ammonium compounds have also been employed as anadditive in a variety of household products including detergents. SeeU.S. Pat. Nos. 3,093,591, 3,560,390, 4,272,395 and 4,576,729.

An effort to remedy the issues faced by prior antimicrobial compositionswas posed in the commonly owned U.S. patent application Ser. No.08/833,276, filed Apr. 4, 1997, of Boli Zhou et al., the disclosure ofwhich is incorporated herein by reference. This Patent Applicationcontemplated the formation of a novel mixed anionic/cationic polymerhaving residual antimicrobial efficacy. However, the application did notdisclose, suggest or teach that an aerosol composition containing amixture of an anionic polymer and a quaternary ammonium compound hasboth disinfectancy (contact efficacy) and residual antimicrobialefficacy. There are also various compositions, especially hard surfacecleaners, which have been delivered as aerosols but which do not containthe inventive mixture of an anionic polymer and a quaternary ammoniumcompound having both disinfectancy (contact efficacy) and residualantimicrobial efficacy.

SUMMARY OF THE INVENTION

The invention is an antimicrobial dispensable composition comprising:

(a) an anionic polymer or prepolymer;

(b) a quaternary ammonium compound, the components (a) and (b) combiningto form an antimicrobially effective complex;

(c) at least one water-soluble or dispersible organic solvent having avapor pressure of at least 0.001 mm Hg at 25° C., said at least oneorganic solvent present in a solubilizing--or dispersion--effectiveamount;

(d) an effective amount of a propellant; and

(e) the remainder, water.

In one aspect, the invention is directed to a dispensable compositionfor treating surfaces which contain microorganisms.

In another aspect, the invention is directed to a method fordecontaminating a surface containing microorganisms by contacting thesurface with the dispensable composition.

In a further aspect, the invention is directed to a device, fordispensing a composition for treating a surface containingmicroorganisms, which includes, a pressurized closed containercontaining the above antimicrobial composition and nozzle means forreleasing said composition towards a contaminated surface.

It is therefore an object and an advantage of the present invention toprovide antimicrobial composition which has both disinfectancy (contactefficacy) and residual antimicrobial efficacy.

It is another object and another advantage of the present invention toprovide a convenient and easy to use product which has prolongedresidual efficacy in a single treatment of surfaces, which thus reduceslabor, time, effort and cost to treat such surfaces.

It is a further object and advantage of the present invention to providea method for decontaminating a surface containing microorganisms, orwhich can be potentially contaminated thereafter.

It is a still further object and advantage of this invention to providea dispensable antimicrobial composition which contacts a surface andforms thereon a film or residue which has prolonged antimicrobialefficacy.

It is yet another object and advantage of this invention to provide adispensable antimicrobial composition which has up to 99.9% residualefficacy in a 24 hour period.

It is a final object and advantage of this invention to provide adispensable antimicrobial composition which outperforms commerciallyavailable products which claim to have antimicrobial efficacy.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides an aerosol formulation comprising a novelantimicrobial composition for treating one or more surfaces containingmicroorganisms. These surfaces include those which are typicallycontacted by human touch: bathroom surfaces, such as a bath tub, sink,commode, toilet, or shower stall, which may have glass doors, andinclude vertical wall surfaces typically made of tile, glass, orcomposite materials; kitchen surfaces, such as countertops, stove tops,sinks, table tops, chairs; and generally, any other surface, whetherhard or soft, such as furniture, window ledges, window frames and otheredges, door knobs, handles, tools, appliances, utility devices (such astelephone handsets and portable telephones), implements (such as pens,mechanical pencils and the like), wrist watches, clothing (such asstockings), shoes, outer garments, and other common and uncommonsurfaces. Each of these types of surfaces can act to harbormicroorganisms, including bacteria, fungi, molds, mildew and viruses.Thus, each such surface can communicate a potential infectious vector tothe unwitting person (or, in the case of cross-species infection,household pets) unless treated with an appropriate antimicrobialcomposition. The inventive antimicrobial composition is intended to sotreat and decontaminate such surfaces, and others, by aerosolapplication of a metered discrete amount of the composition via adispenser onto the surface to be treated. The antimicrobial compositionis generally merely applied as an aerosol composition to the surface inorder to effect antimicrobial efficacy. The surface can additionally bespread or wiped, but this would then remove the composition and maylessen the efficacy thereof.

The antimicrobial composition is formulated with ingredients whichthemselves are found often in cleaners, such as hard surface and fabriccleaners. Thus, an additional benefit of the composition is that it canalso act as a cleaner and soil remover. It is preferred that thisbenefit be achieved without detriment to its primary advantage as anantimicrobial composition.

The aerosol formulation comprises an antimicrobial composition that ismixed with a propellant. The composition has the following ingredients:

(a) an anionic polymer or prepolymer;

(b) a quaternary ammonium compound, the components (a) and (b) combiningto form an antimicrobially effective complex;

(c) at least one water-soluble or dispersible organic solvent having avapor pressure of at least 0.001 mm Hg at 25° C., said at least oneorganic solvent present in a solubilizing--or dispersion--effectiveamount;

(d) an effective amount of a propellant; and

(e) the remainder, water.

Additional adjuncts in small amounts such as buffers, fragrances, dyesand the like can be included to provide desirable attributes of suchadjuncts.

In the application, effective amounts are generally those amounts listedas the ranges or levels of ingredients in the descriptions which followhereto. Unless otherwise stated, amounts listed in percentage ("%'s")are in weight percent (based on 100% active) of the cleaningcomposition.

1. Anionic Polymer or Prepolymer

The anionic polymer or prepolymer (generally, component) generally hasan acid number greater than 10. It is an essential part of the inventionsince it combines with the quaternary ammonium compound in a mechanismwhich, as yet, is not completely understood, and may or may not involvean ionic bonding, or pairing, mechanism. The anionic component isusually a polymer having an average molecular weight of about 100 toabout 2,000,000 daltons, with an acid number preferably greater thanabout 10. As used herein, "acid number" retains its conventional meaningand is determined by the number of milligrams of potassium hydroxiderequired for the neutralization of the corresponding acids of theanionic groups present in one gram of the polymer.

In the antimicrobial composition, the anionic component may or may notbe partially or completely neutralized by the quaternary ammoniumcompound to form a polymer complex. The actual manner of combining ofthe two key components of the inventive antimicrobial compositions hasnot been fully determined at this time. Thus, instead of ionic bonding,as in the classic sense of anionic and cationic materials forming an ionpair (See Cationic Surfactants, Physical Chemistry, in: SurfactantScience Series Vol. 37, p. 93 (Marcel Dekker, 1983)), when the liquid,dispensable compositions of this invention are delivered from thedispenser to a surface, physical association may actually be takingplace, such as occlusion, where the quaternary ammonium compound isevenly dispersed in the resulting polymer matrix or film. It is alsospeculated that, in the dispenser, the components may also form anotherstate in which ion pairing does take place. However, all of theforegoing is by way of non-binding theory.

The antimicrobial composition is preferably prepared by mixing effectiveamounts of the anionic component and the quaternary ammonium compound inwater with agitation. A water miscible solvent and/ordispersing/emulsifying/wetting agent is preferably added before the twomain components are mixed together. The "dispersing/emulsifying/wettingagent" comprises any suitable agent which will cause the admixture ofanionic component and the quaternary ammonium compound to be stablydistributed substantially homogeneously in the liquid composition.Depending on the particular anionic components and quaternary ammoniumcompounds used to make the composition, the presence of cross-linkers,stabilizers and other variables, the antimicrobial compositions of theinvention may exist as emulsions, suspensions, dispersions, solutions,or possibly, as other forms of liquids, such as microemulsions andliquid crystals.

The anionic component, which can be a polymer or prepolymer, ispreferably derived from monomers having anionic groups attached thereto.Preferably, the polymer has an average molecular weight of about 200 to2,000,000, more preferably, about 2,000 to 1,000,000, and mostpreferably, about 5,000 to 150,000 daltons, with an acid number greaterthan about 10 and preferably from about 60 to 700.

Preferred anionic polymers are selected from the group consisting of:(1) a homopolymer that is selected from the group consisting of vinylsulfonates, acrylates, methacrylates, styrene sulfonates, maleates,vinyl sulfates and mixtures thereof; (2) a copolymer that is derivedfrom (i) one or more anionic monomers selected from the group consistingof vinyl sulfonates, acrylates, methacrylates, styrene sulfonates,maleates, vinyl sulfates; and (ii) one or more nonionic monomersselected from vinyl esters, vinyl alcohols, vinyl ethers, acrylamides,methacrylamides, alkyl or aryl acrylates, alkyl or aryl methacrylates,alkyl or aryl maleates, acrylonitriles, vinyl pyrrolidones, alkenes,such as, for example, styrene, ethylene and propylene, multifunctionalacids, polyols, multifunctional amines, multifunctional isocyanates andmultifunctional epoxy compounds; and

(3) methylcarboxycellulose.

As is apparent, copolymers may include nonionic monomers. A preferredcopolymer comprising nonionic and anionic monomers is formed fromacrylic acid esters, such as methacrylate or acrylate. The anionicpolymers can be in their salt, acid, or partially protonated forms.

The solubility/dispersability of the polymer will depend, in part, onits molecular weight, acid number, and the solvent and/orwetting/dispering/emulsifying agent involved. Optionally, the anionicpolymer or component may be cross-linked with common cross-linkers suchas, for example, carbodiimide, aziridine, polyols, glyoxal, epoxycompounds, transition metal ions, and ionene polymers (See also thecross-linking agents described in U.S. patent application Ser. No.09/023,093, filed Feb. 13, 1998, of Shaheen et al., incorporated hereinby reference) to reduce solubility. Typically, in formulating a liquid,dispensable antimicrobial composition, the anionic polymer is present inan amount of about 0.01 to 15%, more preferably about 0.1 to 10%, andmost preferably, about 0.5 to 5%, by weight of the composition.Important examples of the preferred anionic polymers include theacrylate copolymers produced by B.F. Goodrich under the trademarkCarboset. Especially preferred is Carboset Ga. 2123, which appears to bean acrylic acid/acrylate ester copolymer. There further appears to be apreferential ratio of the anionic component to the quaternary ammoniumcompound. This ratio may be from about 1:100 to about 100:1, morepreferably about 1:10 to about 10:1, and most preferably, about 5:1 toabout 1:5. In balancing the ratio of anionic component to quaternaryammonium compound, one must keep in mind the desirable characteristicsin the dispenser (i.e., "can stability") versus that of the dispensedliquid versus that of the cured or dried film/residue (when theliquids/solvents volatilize or "flash off"). The more anionic polymer,the smoother, glassier appearing of the resulting film, and the morewater soluble. The more quaternary ammonium compound, the less watersoluble the resulting film, but, aesthetics of the film appear to becomeless pleasing, however, such less attractive forms are still part of theinvention. The most preferred range of 5:1 to 1:5 appears to result inan aesthetically pleasing film which has excellent residualantimicrobial efficacy, as well as disinfectancy. This also seems toimply that, in the cured film/residue, there may actually not becomplete ion pairing between the quaternary ammonium compound and theanionic sites in the anionic polymer, since the quaternary ammoniumactive sites are available for residual microbial kill, although thereis clearly an interaction between the two components. Again, themechanism of the film/residue is not completely understood, so theselatter observations are made by way of non-binding theory. Further, itis preferred to obtain a transparent to translucent, smooth,homogeneous, tack-free film. So, other additives can be added to improvethe film's characteristics, such as the use of various water solublepolymers, and by neutralizing some of the acid groups of the anionicpolymers by various buffers, such as alkali metal (Na⁺, K⁺) and ammoniumbuffers, although organic buffers, such as alkanolamines may be used.Additionally, some wetting/dispersing/emulsifying agents as describedbelow in 4. help to enable the formation of effective films or residues,by placing the ingredients into dispersion. By "effective" is meant thatthe films achieve consistent residual efficacy throughout the film.

2. Quaternary Ammonium Compound

A critical second component of the invention is a quaternary ammoniumcompound, or surfactant. These types of surfactants are typically usedin bathroom cleaners because they are generally considered "broadspectrum" antimicrobial compounds, having efficacy against both grampositive (e.g., Staphylococcus sp.) and gram negative (e.g., Escherichiacoli or Klebsiella sp.) microorganisms. Thus, the quaternary ammoniumsurfactant, or compounds, are incorporated forbacteriostatic/disinfectant purposes and should be present in amountseffective for such purposes.

The quaternary ammonium compounds are selected from mono-long-chain,tri-short-chain, tetraalkyl ammonium compounds, di-long-chain,di-short-chain tetraalkyl ammonium compounds, trialkyl, mono-benzylammonium compounds, and mixtures thereof. By "long" chain is meant aboutC₆₋₃₀ alkyl. By "short" chain is meant about C₁₋₅ alkyl, preferablyC₁₋₃. Suitable counterions for such quaternary ammonium compoundsinclude halides (chlorides, bromides, iodides), hydroxides,saccharinates, carbonates, phosphates, phosphonates, sulfates,bisulfates, alkylsulfates, carboxylates, and other negatively chargedcounterions. Preferred materials include the BTC 885--which comprises amixture of C₁₂₋₁₆ alkyl dimethylbenzyl ammonium chloride, C₈ /C₁₀ alkyldimethyl ammonium chloride, di-C₈ alkyl dimethyl ammonium chloride, anddi-C₁₀ alkyl dimethyl ammonium chloride--and 2125 series from Stepan,which comprises di-C₂₄ -dialkyl ammonium chloride, and the Barquat andBardac series, such as Bardac MB 2050, from Lonza Chemical. Mostpreferred appears to be a mixed quaternary ammonium surfactant in whichthere is a combination of di-long-chain, di-short-chain tetraalkylammonium compounds, and trialkyl, mono-benzyl ammonium compounds. Theseparticularly preferred quaternary ammonium surfactants form both smoothfilms with the anionic polymers listed above, but also are the mosteffective at broad spectrum contact and residual antimicrobial efficacy(both gram negative and gram positive microorganisms), antifungal andantiviral efficacy. Typical amounts of the quaternary ammonium compoundrange from preferably about 0.01-5%, more preferably about 0.01-2%.

3. Solvents

The solvent is a water soluble or dispersible organic solvent having avapor pressure of at least 0.001 mm Hg at 25° C. It is preferablyselected from C₁₋₆ alkanols, C₁₋₆ diols, C₁₋₆ alkyl ethers of alkyleneglycols and polyalkylene glycols, and mixtures thereof. The alkanol canbe selected from methanol, ethanol, n-propanol, "isopropanol," thevarious positional isomers of butanol, pentanol, and hexanol, andmixtures of the foregoing. It may also be possible to utilize inaddition to, or in place of, said alkanols, the diols such as methylene,ethylene, propylene and butylene glycols, and mixtures thereof, andincluding polyalkylene glycols.

It is preferred to use a C₁₋₆ alkanol solvent in this invention. Thepreferred alkanol is ethanol, which advantageously acts as both asolvent, to maintain the ingredients in the liquid composition indispersion, as well as a disinfectant. If mixtures of solvents are used,the amounts and ratios of such solvents used are important to determinethe optimum performances of the inventive composition. It is preferredto have the total amount of solvent to at least 20%, more preferablyleast 30%, and most preferably, at least 50%, of the composition. Apreferred range is about 20-99.9%. These amounts of solvents aregenerally referred to as dispersion effective or solubilizing effectiveamounts, since the other components, such as surfactants, are materialswhich are assisted into solution by the solvents. As in the case ofethanol, the solvent can also have disinfectancy capacity itself.Finally, the solvent is also important as a cleaning materials itself,helping to loosen and solubilize certain soils for easy removal from thesurface treated.

4. Wetting/Emulsifying/Dispersing Agent

The wetting/emulsifying/dispersing agent may be preferably a surfactant(preferably, anionic, cationic nonionic, amphoteric, or zwitterionicsurfactant; but the quaternary ammonium surfactant of 2., above, is notconsidered as one of the wetting agents herein), or possibly, ahydrotrope (which is also treated below, in 5.). The surfactant may bean nonionic, amphoteric or zwitterionic surfactant, or mixtures thereof.The following is a nonlimiting description of surfactants which might beemployed in the present invention. The description is intended toexemplify that a wide variety of surfactants can be used according tothe present invention.

a. Anionic, Nonionic, Amphoteric and Zwitterionic Surfactants

The anionic surfactants may include a negatively charged watersolubilizing group.

The nonionic surfactants may be selected from modified polysiloxanes,alkoxylated alcohols, alkoxylated phenol ethers, glycosides, and thelike. Trialkyl amine oxides, and other surfactants often referred to as"semi-polar" nonionics, may also be employed.

Most preferred are modified polysiloxanes. The modified polysiloxane canbe an alkoxylated dimethylsiloxane, such as those available from BykChemie, such as BYK-345.

The alkoxylated alcohols may include, for example, ethoxylated, andethoxylated and propoxylated C₆₋₁₆ alcohols, with about 2-10 moles ofethylene oxide, or 1-10 and 1-10 moles of ethylene and propylene oxideper mole of alcohol, respectively. Exemplary surfactants are availablefrom Shell Chemical under the trademarks Neodol and Alfonic, and fromHuntsman Chemicals under the trademark Surfonic (e.g., Surfonic L12-6, aC₁₀₋₁₂ ethoxylated alcohol with 6 moles of ethylene oxide, and SurfonicL12-8, a C₁₀₋₁₂ ethoxylated alcohol with 8 moles of ethylene oxide).

The alkoxylated phenol ethers may include, for example, octyl- andnonylphenol ethers, with varying degrees of alkoxylation, such as 1-10moles of ethylene oxide per mole of phenol. The alkyl group may vary,for example, from C₆₋₁₆, with octyl- and nonyl chain lengths beingreadily available. Various suitable products are available from Rohm &Haas under the trademark Triton, such as Triton N-57, N-101, N-111,X-45, X-100, X-102, from Mazer Chemicals under the trademark Macol, fromGAF Corporation under the trademark Igepal, and from Huntsman under thetrademark Surfonic.

The glycosides, particularly the alkyl polyglycosides, may also be usedas a surfactant for purposes of the aerosol formulation of the presentinvention. These glycosides include those of the formula:

    RO(C.sub.n H.sub.2n O).sub.y (Z).sub.x

wherein R is a hydrophobic group (e.g., alkyl, aryl, alkylaryl etc.,including branched or unbranched, saturated and unsaturated, andhydroxylated or alkoxylated members of the foregoing, among otherpossibilities) containing from about 6 to about 30 carbon atoms,preferably from about 8 to about 15 carbon atoms, and more preferablyfrom about 9 to about 13 carbon atoms; n is a number from 2 to about 4,preferably 2 (thereby giving corresponding units such as ethylene,propylene and butylene oxide); y is a number having an average value offrom 0 to about 12, preferably 0; Z is a moiety derived from a reducingsaccharide containing 5 or 6 carbon atoms (e.g., a glucose, fructose,mannose, galactose, talose, gulose, allose, altrose, idose, arabinose,xylose, lyxose, or ribose unit, etc., but most preferably a glucoseunit); and x is a number having an average value of from 1 to about 10,preferably from 1 to about 5, and more preferably from 1 to about 3.

It would be apparent that a number of variations with respect to themakeup of the glycosides are possible. For example, mixtures ofsaccharide moieties (Z) may be incorporated into polyglycosides. Also,the hydrophobic group (R) can be attached at the 2-, 3-, or 4-positionsof a saccharide moiety rather than at the 1-position (thus giving, forexample, a glucosyl as opposed to a glucoside). In addition, normallyfree hydroxyl groups of the saccharide moiety may be alkoxylated orpolyalkoxylated. Further, the (C_(n) H_(2n) O)_(y) group may includeethylene oxide and propylene oxide in random or block combinations,among a number of other possible variations.

An exemplary glycoside surfactant is APG 325n, which is manufactured bythe Henkel Corporation. APG 325n is a nonionic alkyl polyglycoside inwhich R is a mixture of Cg, C₉, C₁₀ and C₁₁ chains in a weight ratiorespectively of 20:40:40 (equivalent to an average of Cl₁₀.2), with x of1.6, and an HLB of 13.1.

Compositions containing other surfactants, such as some amine oxides,may be less compatible with the tin-plated steel can environment (oreven with steel cans that are lined with, e.g., an epoxy phenoliccoating). Tin-plated steel cans are desirable as containers for aerosolcompositions because they are more readily available and are lessexpensive than aluminum or specially lined steel cans.

The amine oxides, referred to as mono-long chain, di-short chain,trialkyl amine oxides, have the general configuration: ##STR1## whereinR¹ is C₆₋₂₄ alkyl, and R² and R³ are both C₁₋₄ alkyl, or C₁₋₄hydroxyalkyl, although R² and R³ do not have to be equal. These amineoxides can also be ethoxylated or propoxylated. The preferred amineoxide is lauryl amine oxide. The commercial sources for such amineoxides are Barlox 10, 12, 14 and 16 from Lonza Chemical Company, Varoxby Witco and Ammonyx by Stepan Company.

A further semi-polar nonionic surfactant isalkylamidoalkylenedialkylamine oxide. Its structure is shown below:##STR2## wherein R¹ is C₅₋₂₀ alkyl, R² and R³ are C₁₋₄ alkyl, R¹--C--NH--(CH₂)_(n) -- or --(CH₂)_(p) --OH, although R² and R³ do nothave to be equal or the same substituent, and n is 1-5, preferably 3,and p is 1-6, preferably 2-3. Additionally, the surfactant could beethoxylated (1-10 moles of EO/mole) or propoxylated (1-10 moles ofPO/mole). This surfactant is available from various sources as acocoamidopropyldimethyl amine oxide; it is sold by Lonza ChemicalCompany under the brand name Barlox C. Additional semi-polar surfactantsmay include phosphine oxides and sulfoxides.

A preferred cationic surfactant is morpholinium ethosulfate, such asForestall (Atlas) G-271.

The amphoteric surfactant is typically an alkylbetaine, an amidobetaine,or a sulfobetaine. One group of preferred amphoterics arealkylamidoalkyldialkylbetaines. These have the structure: ##STR3##wherein R¹ is C₆₋₂₀ alkyl, R² and R³ are both C₁₋₄ alkyl, although R²and R³ do not have to be equal, and m can be 1-5, preferably 3, and ncan be 1-5, preferably 1. These alkylbetaines can also be ethoxylated orpropoxylated. The preferred amidobetaine is cocoamidopropyldimethylbetaine, available from Lonza Chemical Co. as Lonzaine CO. Other vendorsare Henkel KGaA, which provides Velvetex AB, and Witco Chemical Co.,which offers Rewoteric AMB-15, both of which products are cocobetaines.

Potentially suitable zwitterionic surfactants can be found described inJones, U.S. Pat. No. 4,005,029, at columns 11-15, which are incorporatedherein by reference.

The amounts of surfactants present are to be somewhat minimized, forpurposes of cost-savings and to generally restrict the dissolved activeswhich could contribute to leaving behind residues when the aerosol isapplied to a surface. However, the amounts added are generally about0.001-5%, more preferably 0.002-3.00% surfactant. These are generallyconsidered to be dispersion-effective amounts.

5. Water and Miscellaneous

Since the composition is an aqueous composition, water can be, alongwith the solvent, be a predominant ingredient. The water should bepresent at a level of less than 70%, more preferably less than about65%, and most preferably, less than about 50%. Deionized water ispreferred.

Small amounts of adjuncts can be added for improving performance,stability or aesthetic qualities of the composition. For example,buffers can be added to maintain a constant pH (which for the inventionis between about 5-14, more preferably between about 8-13; formulationscontaining the tripotassium and/or triammonium salts will naturally beat a lower end of the range as compared to the corresponding tetrasalts). These buffers include, for example, NaOH, KOH, Na₂ CO₃, and K₂CO₃ as alkaline buffers, and phosphoric, hydrochloric, sulfuric, andcitric acids as acidic buffers, among others. It may be desirable to addchelating agents, such as polycarboxylates (e.g., EDTA and its alkalimetal and ammonium salts), aminopolyphosphonates and polyphosphonates,metasilicates and organic amines. Chelating agents may help topotentiate antimicrobial efficacy or have other functional uses.

Further solubilizing materials, such as hydrotropes (e.g., water solublesalts of low molecular weight organic acids such as the sodium orpotassium salts of cumene-, toluene-, benzene-, and xylene sulfonicacid), may also be desirable. Adjuncts for cleaning include additionalsurfactants, such as those described in Kirk-Othmer, Encyclopedia ofChemical Technology, 3rd Ed., Volume 22, pp. 332-432 (Marcel-Dekker,1983), and McCutcheon's Soaps and Detergents (N. Amer. 1984), which areincorporated herein by reference. Aesthetic adjuncts include fragrancesor perfumes, such as those available from Givaudan, IFF, Quest, Sozio,Firmenich, Dragoco and others, and dyes or colorants which can besolubilized or suspended in the formulation, such asdiaminoanthraquinones. Enhancing ingredients, such as nerolidol, may bepresent to perform in multiple capacities, both aesthetic andfunctional, the composition (See commonly owned U.S. patent applicationSer. No. 09/085,340, of Shaheen et al., filed May 27, 1998, andincorporated herein by reference). Water-insoluble solvents maysometimes be desirable as added grease- or oily soil-cutting agents.These types of solvents include tertiary alcohols, hydrocarbons (e.g.,alkanes), pine-oil, d-limonene and other terpenes and terpenederivatives, and benzyl alcohols. Thickeners, such as calcium carbonate,sodium bicarbonate, aluminum oxide, and polymers, such as polyacrylate,starch, xanthan gum, alginates, guar gum, cellulose, and the like, maybe desired additives, although care must be taken since the inventivecompositions are meant to be relatively thin liquids for effectivedispensation from a pressurized canister. The use of some of thesethickeners (e.g., CaCO₃ or NaHCO₃) is to be distinguished from theirpotential use as builders, generally by particle size or amount used.Additional additives may include further antimicrobial compounds, suchas phenols (See, Moseman, U.S. Pat. No. 4,985,945, incorporated hereinby reference), pine oil (See Spaulding et al., U.S. Pat. No. 4,867,898,incorporated herein by reference) and liposome-like microemulsions suchas mentioned in the paper by T. Hamouda et al., "Microbiocidal Effectsof Liposomes-Like Microemulsions on Pathogenic Gram Negative Bacteria,"in: Poster Session 251/A Antimicrobial Therapy and Charactertization ofPathogens, American Society of Microbiology 98th Annual Meeting, May17-21, 1998, p. 152, said paper incorporated herein by reference.

As already noted above, the preferred container for dispensing of thepresent composition in aerosol form is a tin-plated steel can, but otheraerosol packages may be suitable for use. Therefore, it is advantageousto add one or more corrosion inhibitors to prevent or at least reducethe rate of expected corrosion of such a metallic dispenser. Chloridesalts, if present, may cause corrosion. Preferred corrosion inhibitorsinclude, for example, sodium nitrite, potassium nitrite, sodiumbenzoate, potassium benzoate, amine neutralized alkyl acid phosphatesand nitroalkanes, amine neutralized alkyl acid phosphates and volatileamines, diethanolamides, amine borates, hydroxylamines, alkanolamines,amine carboxylates, esters, volatile silicones, amines and mixturesthereof. Specific inhibitors include, for example, sodium lauroylsarcosinate, available from Stepan Company under the trademark Maprosyl30, sodium meta silicate, sodium or potassium benzoate, triethanolamine,and morpholine. When employed, the corrosion inhibitor preferablycomprises about 0.01% to 5% of the aerosol formulation.

6. Propellant

The antimicrobial composition is delivered in the form of an aerosol.The propellant comprises, for example, a hydrocarbon, of from 1 to 10carbon atoms, such as methane, ethane, n-propane, n-butane, isobutane,n-pentane, isopentane, and mixtures thereof. The propellant may also beselected from halogenated hydrocarbons including, for example,fluorocarbons, chlorocarbons, chlorofluorocarbons, and mixtures thereof.(Besides of concerns about the destruction of the stratosphere's ozonelayer, the use of fluorocarbons and chlorofluorocarbons is lesspreferred.) Examples of other suitable propellants are found in P. A.Sanders Handbook of Aerosol Technology (Van Nostrand Reinhold Co.)(1979) 2nd Ed., pgs. 348-353 and 364-367, which are incorporated byreference herein. Further, non-hydrocarbon propellants may be possible,such as carbon dioxide, nitrogen, compressed air, and, possibly, denseor supercritical fluids.

A liquefied gas propellant mixture comprising about 85% isobutane and15% propane is preferred because it provides sufficient pressure toexpel the cleaning composition from the container and provides goodcontrol over the nature of the spray upon discharge of the aerosolformulation. Preferably, the propellants comprises about 1% to 50%, morepreferably about 2% to 25%, and most preferably about 5% to 15% of theaerosol formulation.

The aerosol formulation is preferably stored in and dispensed from apressurized can that is equipped with a nozzle so that an aerosol of theformulation can be readily sprayed onto a surface. Dispensers are knownin the art and are described, for example, in U.S. Pat. Nos. 4,780,100,4,652,389, and 3,541,581 which are incorporated by reference herein.Although pressure within the dispenser, i.e., can pressure, does notappear to be critical, it may be preferred to range from about 10 to 100psig. at 70° F. (21.1° C.).

In loading the dispenser, the non-propellant components of the aerosolformulation are mixed into a concentrate and loaded into the dispenserfirst. Thereafter, the liquefied gaseous propellant is inserted beforethe dispenser is fitted with a nozzle.

EXPERIMENTAL

In the following Table I, the preferred composition of the invention isdisclosed:

                  TABLE I                                                         ______________________________________                                        Ingredient            wt. % active                                            ______________________________________                                        Buffer (NaOH)         0.007                                                   Dispersing/emulsifying/wetting agent.sup.1                                                          0.03                                                    Fragrance.sup.2       0.25                                                    Corrosion Inhibitor.sup.3                                                                           0.6                                                     Quaternary Ammonium Compound.sup.4                                                                  0.63                                                    Anionic Polymer.sup.5 1.05                                                    Propellant.sup.6      10                                                      Water                 122.433                                                 Ethanol               65                                                      Total                 100                                                     ______________________________________                                         .sup.1 Byk Chemie BYK345                                                      .sup.2 Proprietary                                                            .sup.3 NaNO2                                                                  .sup.4 Stepan BTC885                                                          .sup.5 B. F. Goodrich GA 2123                                                 .sup.6 Diversified CPC Int'l A46                                         

The films resulting from the dispensing and curing of this formulationresulted in elegant, smooth, glassy appearing translucent films whichdemonstrated good water resistance. However, it is the disinfectancy andresidual efficacy performance which was especially noteworthy andunexpected.

In the following experiments, it should be noted that disinfectancy(contact efficacy or kill) is assessed by a 10 minute contact on asurface containing a given titer of microorganisms, whose reductionafter 10 minute contact is compared to a control. The residual efficacystudies generally are determined by repeated inoculation of a surfacewith a given microorganism, with rinsing or other removal of materialsfrom the surface between the inoculations, which are adapted fromstandard AOAC/ASTM and other protocols.

The disinfecting (contact efficacy) tests are disclosed in Tables II-Vbelow, in which the inventive formulation is tested against bacteria,viruses and fungi, respectively.

                  TABLE II                                                        ______________________________________                                        Bacterial Disinfectancy                                                                         Number of carriers                                                                           Showing                                      Lot Number Organism     Exposed  Growth                                       ______________________________________                                        Lot #1     Staphylococcus                                                                             60       1° 0                                             aureus                2° 0                                             Salmonella   60       1° 0                                             choleraesuis          2° 0                                             Pseudomonas  60       1° 0                                             aeruginosa            2° 0                                  Lot #2     Staphylococcus                                                                             60       1° 0                                             aureus                2° 0                                             Salmonella   60       1° 0                                             choleraesuis          2° 0                                             Pseudomonas  60       1° 0                                             aeruginosa            2° 0                                  Lot #3     Staphylococcus                                                                             60       1° 0                                             aureus                2° 0                                             Salmonella   60       1° 0                                             choleraesuis          2° 0                                             Pseudomonas  60       1° 0                                             aeruginosa            2° 0                                  ______________________________________                                         1° = primary subculture growth; 2° = secondary subculture       growth.                                                                  

The inventive composition resulted in complete inactivation of eachviral strain. The exemplary performance results are demonstrated belowin Table III.

                  TABLE III                                                       ______________________________________                                        Virucidal Efficacy                                                                          Lot 3   Lot 4                                                         Dried   Virus   Virus Cyto- Cyto- Virus                                       Virus   Expo-   Expo- toxicity                                                                            toxicity                                                                            Reduction                             Virus Control sure    sure  Lot 3 Lot 4 Titer                                 ______________________________________                                        Polio-                                                                              10.sup.6.75                                                                           ≦10.sup.2.5                                                                    ≦10.sup.2.5                                                                  ≦10.sup.2.5                                                                  ≦10.sup.2.5                                                                  ≧4.25 log.sub.10               virus                                   Complete                              type 1                                  Inactivation                          Influ-                                                                              10.sup.4.75                                                                           ≦10.sup.1.5                                                                    ≦10.sup.1.5                                                                  ≦10.sup.1.5                                                                  ≦10.sup.1.5                                                                  ≧3.25 log.sub.10               enza                                    Complete                              Virus                                   Inactivation                          type                                                                          A2                                                                            HIV   10.sup.6.5                                                                            ≦10.sup.3.5                                                                    ≦10.sup.3.5                                                                  ≦10.sup.3.5                                                                  ≦10.sup.3.5                                                                  ≦3.0 log.sub.10                type 1                                  Complete                                                                      Inactivation                          ______________________________________                                    

                  TABLE IV                                                        ______________________________________                                        Anitfungal Efficacy                                                                                     Visual   Magnified                                  Sample                    Evaluation of                                                                          Evaluation of                              Lot    Organism    Tiles  Test Tiles                                                                             Test Tiles                                 ______________________________________                                        Lot 3  Aspergillus niger                                                                         1-10   no growth (0%)                                                                         no growth (0%)                             Lot 4  Aspergillus niger                                                                         1-10   no growth (0%)                                                                         no growth (0%)                             Untreated                                                                            Aspergillus niger                                                                         1-10   growth (75-95%)                                     Control                                                                       Tiles                                                                         ______________________________________                                    

                  TABLE V                                                         ______________________________________                                        Anitfungal Efficacy                                                                            Number of Carriers                                           Sample                          Showing                                       Lot     Organism       Exposed  Growth                                        ______________________________________                                        Lot 3   Tricophyton    10       1° 0                                           metagrophytes           2° 0                                   Lot4    Tricophyton    10       1° 0                                           metagrophytes           2° 0                                   ______________________________________                                    

The residual efficacy results are captured below in Tables VI-XI. TablesVI and IX show the controls in which bacterial growth are observed,Tables VII and X show the residual efficacy data, and Tables VIII and XIshow reduction calculations. In the data, "CFU" means "colony formingunits, a standard measure in microbiology.

                  TABLE VI                                                        ______________________________________                                        Control Counts                                                                Test     Carrier   Zero Time Counts -                                                                         Control Counts -                              Organism Designation                                                                             CFU/Carrier  CFU/Carrier                                   ______________________________________                                        Stapylococcus                                                                          A         6.4 ×                                                                           10.sup.5                                                                             1.4 ×                                                                         10.sup.6                              aureus   B         5.3 ×                                                                           10.sup.5                                                                             9.3 ×                                                                         10.sup.5                                       C         Avg =   5.9 × 10.sup.5                                                                 Avg. =                                                                              1.0 × 10.sup.6                  Klebsiella                                                                             A         1.4 ×                                                                           10.sup.6                                                                             1.3 ×                                                                         10.sup.6                              pneumoniae                                                                             B         1.5 ×                                                                           10.sup.6                                                                             1.6 ×                                                                         10.sup.6                                                 Avg. =  1.5 × 10.sup.6                                                                 Avg. =                                                                              1.6 × 10.sup.6                           C                        2.0 ×                                                                         10.sup.6                              ______________________________________                                    

                  TABLE VII                                                       ______________________________________                                        Test Substance Tile Counts                                                    Test      Test          Carrier No. of                                        Sample No.                                                                              Organism      Code    CFU/Carrier                                   ______________________________________                                        L1-6      Staphylococcus                                                                              A        15                                                     aureus        B       no observable                                                                 colonies                                                              C        45                                           L1-6      Klebsiella    A       690                                                     pneumoniae    B       135                                                                   C       660                                           L2-1      Staphylococcus                                                                              A        30                                                     aureus        B        45                                                                   C        75                                           L2-1      Klebsiella    A       195                                                     pneumoniae    B       195                                                                   C       135                                           ______________________________________                                    

                  TABLE VIII                                                      ______________________________________                                        % Reduction Calculations                                                      Test      Test          Carrier % Reduction                                   Sample No.                                                                              Organism      Code    vs. Control                                   ______________________________________                                        L 1-6     Staphylococcus                                                                              A       99.9                                                    aureus        B       >99.9                                                                 C       99.9                                          L 1-6     Klebsiella    A       99.9                                                    pneumoniae    B       99.9                                                                  C       99.9                                          L2-1      Staphylococcus                                                                              A       99.9                                                    aureus        B       99.9                                                                  C       99.9                                          L2-1      Klebsiella    A       99.9                                                    pneumoniae    B       99.9                                                                  C       99.9                                          ______________________________________                                    

                  TABLE IX                                                        ______________________________________                                        Control Counts                                                                               Carrier   Control Counts -                                     Test Organism  Designation                                                                             CFU/Carrier                                          ______________________________________                                        Salmonella     A         2.5 × 10.sup.5                                 choleraesuis   B         1.9 × 10.sup.5                                                C         4.8 × 10.sup.5                                 Escherichia coli                                                                             A         6.4 × 10.sup.5                                 0157:H7        B         5.8 × 10.sup.5                                                C         6.4 × 10.sup.5                                 ______________________________________                                    

                  TABLE X                                                         ______________________________________                                        Test Substance Tile Counts                                                                   Carrier No. of                                                 Test Organism  Code    CFU/Carrier                                            ______________________________________                                        Salmonella     A       315                                                    choleraesuis   B       450                                                                   C       195                                                    Escherichia coli                                                                             A        30                                                    0157:117       B        30                                                                   C       no observable colonies                                 ______________________________________                                    

                  TABLE XI                                                        ______________________________________                                        % Reduction Calculations                                                      Test             Carrier % Reduction                                          Organism         Code    vs. Control                                          ______________________________________                                        Salmonella       A       99.9                                                 choleraesuis     B       99.9                                                                  C       99.9                                                 Escherichia coli A       99.9                                                 0157:H7          B       99.9                                                                  C       >99.9                                                ______________________________________                                    

The foregoing data in Tables VIII and XI demonstrate generally excellentbroad spectrum residual efficacy versus both gram negative and grampositive bacteria.

The foregoing has described the principles, preferred embodiments andmodes of operation of the present invention. However, the inventionshould not be construed as being limited to the particular embodimentsdiscussed. Thus, the above-described embodiments should be regarded asillustrative rather than restrictive, and it should be appreciated thatvariations may be made in those embodiments by workers skilled in theart without departing from the scope of the present invention as definedby the following claims.

What is claimed is:
 1. An aerosol antimicrobial dispensable compositioncomprising:(a) about 0.01 to 15% of an anionic polymer or prepolymer,which has an acid number greater than 10 wherein the polymer may becompletely or partly neutralized by a quaternary ammonium compound, saidpolymer having a molecular weight range from 100 to 2,000,000 Daltons;(b) about 0.01 to 5% of said quaternary ammonium compound, thecomponents (a) and (b) combining to form an antimicrobially effectivecomplex; (c) at least one water-soluble or dispersible organic solventhaving a vapor pressure of at least 0.001 mm Hg at 25° C. and selectedfrom the group consisting of C₁₋₆ alkanols, C₁₋₆ diols. C₁₋₆ alkylethers of alkylene glycols and polyalkylene glycols, and mixturesthereof, said at least one organic solvent being at least 20% of thecomposition; (d) about 1% to 50% of a propellant; and (e) less than 70%water.
 2. The composition of claim 1 wherein said anionic polymer orprepolymer is acrylate copolymer.
 3. The composition of claim 1 whereinthe quaternary ammonium compound is selected from the group consistingof mono-long-chain, tri-short-chain, tetraalkyl ammonium compounds,di-long-chain, di-short-chain tetraalkyl ammonium compounds, trialkylmono-benzyl ammonium compounds, and mixtures thereof.
 4. The compositionof claim 3 wherein said quaternary ammonium compound is a mixture oftrialkyl, mono-benzyl ammonium and di-long-chain, di-short-chaintetraalkyl ammonium compounds.
 5. The composition of claim 1 whereinsaid organic solvent of (c) is selected from the group consisting ofalkanols, diols, polyalkylene glycols, alkyl ethers of alkylene glycolsand polyalkylene glycols, and mixtures thereof.
 6. The composition ofclaim 5 wherein said organic solvent is a C₁₋₆ alkanol.
 7. Thecomposition of claim 1 wherein said propellant is selected fromcompressed or compressible gases and hydrocarbon propellants.
 8. Thecomposition of claim 1 further comprising a dispersing, wetting oremulsifying agent.
 9. The composition of claim 8 wherein saiddispersing, wetting or emulsifying agent is selected from anionic,nonionic, cationic, amphoteric surfactants; hydrotropes; and mixturesthereof.
 10. The composition of claim 9 wherein said dispersing, wettingor emulsifying agent is a modified polysiloxane.
 11. The composition ofclaim 1 further comprising at least one adjunct selected from the groupconsisting of corrosion inhibitors, chelants, buffers, fragrances,perfumes, thickeners, dyes, colorants, pigments, water-insoluble organicsolvents, additional antimicrobial compounds, and mixtures thereof. 12.A method for treating a surface containing microorganisms, or whichcould contain said microorganisms thereafter, said method comprising thesteps of:(i) delivering an admixture via a propellant, wherein theadmixture and propellant are derived from an aerosol compositioncomprising:(a) about 0.01 to 15% of an anionic polymer or prepolymer,which has an acid number greater than 10 wherein the polymer may becompletely or partly neutralized by a quaternary ammonium compound, saidpolymer having a molecular weight range from 100 to 2,000,000 Daltons;(b) about 0.01 to 5% of sad quaternary ammonium compound, the components(a) and (b) combining to form an antimicrobially effective complex; (c)at least one water-soluble or dispersible organic solvent having a vaporpressure of at least 0.001 mm Hg at 25° C. and selected from the groupconsisting of C₁₋₆ alkanols, C₁₋₆ diols, C₁₋₆ alkyl ethers of alkyleneglycols and polyalkylene glycols, and mixtures thereof, said at leastone organic solvent being at least 20% of the composition; (d) about 1%to 50% of a propellant; and (e) less than 70% water; and (ii) applyingsaid admixture to a surface.
 13. A device for dispensing an aerosolantimicrobial composition which comprises:a closed container containingsaid composition, said composition comprising:(a) about 0.01 to 15% ofan anionic polymer or prepolymer, which has an acid number greater than10 wherein the polymer may be completely or partly neutralized by aquaternary ammonium compound, said polymer having a molecular weightrange from 100 to 2,000,000 Daltons; (b) about 0.01 to 5% of saidquaternary ammonium compound, the components (a) and (b) combining toform an antimicrobially effective complex; (c) at least onewater-soluble or dispersible organic solvent having a vapor pressure ofat least 0.001 mm Hg at 25° C. and selected from the group consisting ofC₁₋₆ alkanols, C₁₋₆ diols, C₁₋₆ alkyl ethers of alkylene glycols andpolyalkylene glycols, and mixtures thereof, said at least one organicsolvent being at least 20% of the composition; (d) about 1% to 50% of apropellant; and (e) less than 70% water.
 14. A film or residue on asurface from the application of a dispensable antimicrobial compositionto said surface, said aerosol composition comprising:(a) about 0.01 to15% of an anionic polymer or prepolymer, which has an acid numbergreater than 10 wherein the polymer may be completely or partlyneutralized by a quaternary ammonium compound, aid polymer having amolecular weight range from 100 to 2,000,000 Daltons; (b) about 0.01 to5% of said quaternary ammonium compound, the components (a) and (b)combining to form an antimicrobially effective complex; (c) at least onewater-soluble or dispersible organic solvent having a vapor pressure ofat least 0.001 mm Hg at 25° C. and selected from the group consisting ofC₁₋₆ alkanols, C₁₋₆ alkyl ethers of alkylene glycols and polyalkyleneglycols, and mixtures thereof, said at least one organic solvent beingat least 20% of the composition; (d) about 1% to 50% of a propellant;and (e) less than 70% water.